Sciencemadness Discussion Board

Chemicals in feces

forgottenpassword - 23-2-2014 at 13:09

I have been looking for information on the chemical composition of feces with a view to extracting any interesting organic chemicals that may be present in sufficient quantity to make it worthwhile. Surprisingly I have been unable to find very much information of this subject, the best source being the following from the Encyclopedia Britannica:

"Normally, feces are made up of 75 percent water and 25 percent solid matter. About 30 percent of the solid matter consists of dead bacteria; about 30 percent consists of indigestible food matter such as cellulose; 10 to 20 percent is cholesterol and other fats; 10 to 20 percent is inorganic substances such as calcium phosphate and iron phosphate; and 2 to 3 percent is protein. Cell debris shed from the mucous membrane of the intestinal tract also passes in the waste material, as do bile pigments (bilirubin) and dead leukocytes (white blood cells). The brown colour of feces is due to the action of bacteria on bilirubin, which is the end product of the breakdown of hemoglobin (red blood cells). The odour of feces is caused by the chemicals indole, skatole, hydrogen sulfide, and mercaptans, which are produced by bacterial action."

I haven't been able to find a review of the chemical constituents of human or animal feces, but I found a paper on the extraction of nuceic acids which is interesting: http://www.biotechniques.com/multimedia/archive/00010/00282s...

What I would like to find out is the viability of extracting simple organic chemicals, such as skatole, from feces in non-miniscle amounts. If anyone could assist in providing information I would appreciate it.

thesmug - 23-2-2014 at 13:24

There are so many different chemicals that it would be nearly impossible to extract just a single one. You could try if you really have a lot of time available. This would also probably be a serious health hazard so I wouldn't try.

Even at that, if you really want to and have proper protection, you could try. I doubt it would be worth it, though.

DrAldehyde - 23-2-2014 at 13:35

This thread is so ripe for juvenile humor, that I simply could not walk away. If I understand you correctly, you want to extract the smell out of poop? A chemical that could only be named skatole. Well, I wouldn't be talking out my arse if I said I think the whole idea stinks, but, I wish you luck in your endeavor.

thesmug - 23-2-2014 at 13:41

Quote: Originally posted by DrAldehyde  
This thread is so ripe for juvenile humor, that I simply could not walk away. If I understand you correctly, you want to extract the smell out of poop? A chemical that could only be named skatole. Well, I wouldn't be talking out my arse if I said I think the whole idea stinks, but, I wish you luck in your endeavor.

I'm glad you made me look that up. It seems he could get much more of it from tar, so I'm just going to assume this is a joke.

papaya - 23-2-2014 at 14:07

What about nitrates, I've heard ancients extracted them (to make blackpowder), is this true?

thesmug - 23-2-2014 at 15:27

Quote: Originally posted by papaya  
What about nitrates, I've heard ancients extracted them (to make blackpowder), is this true?

Maybe. Do you know about how they went about extracting them?

forgottenpassword - 23-2-2014 at 15:33

I don't know about nitrates. I am more interested in extracing organic chemicals. Skatole and indole are useful chemicals. Odor is a rather silly thing to judge the usefulness of a chemical by. The structure of indole makes it chemically useful, its odor is just its odor.
I think that with selective solvent extractions and chromatography it would be relatively easy to obtain pure products, and feces would likely contain a more concentrated source and range of organic chemicals than the plant and animal products that went into its production. It seems a sensible choice to extract chemicals from a concentrated source. I shall continue to research it anyway.

thebean - 23-2-2014 at 15:37

Indole gives feces it's odor. http://en.wikipedia.org/wiki/Indole#General_properties_and_o...

subsecret - 23-2-2014 at 18:53

Chicken feces were used for nitrates, IIRC.

hyfalcon - 24-2-2014 at 01:40

Chicken feces makes sense. It's the hottest manure, nitrogen wise, that is readily available on the farm.

forgottenpassword - 24-2-2014 at 04:02

I found this citation: http://www.ncbi.nlm.nih.gov/pubmed/8081474 which states that indole and skatole may be extracted with chloroform, and that they are present in the amount of 100 mg per kg of fecal matter. I'm not sure if that is wet or dry but regardless it seems like a good quantity to me. Steeping the feces in chloroform or DCM then decanting and repeating the process seems like a good way to get a concentrated extract, which could then be concentrated and separated on a silica column. I may try it on a small scale using DCM and chloroform separately, and test the extract with TLC. Solvent systems and Rf values for indole and skatole should be easy to find, and would confirm the efficiency of the extraction with each solvent.
Update: I have prepared a sample and have it soaking in DCM. I will let it sit until tomorrow and then do a TLC with whatever I have extracted. The DCM has remained clear so I am hopeful of a fairly selective extraction of skatole and indole. I only have iodine to visualize the TLC plate. If I manage to detect anything with iodine I shall buy some p-dimethylaminobenzaldehyde to prepare Ehrlich's reagent, which will enable me to differentiate the indole from skatole based on the different colors that they produce, along with the Rf values that I found in my TLC handbook. I was only able to prepare one sample due to an unacceptable risk of contaminating the second sample with vomit.

[Edited on 24-2-2014 by forgottenpassword]

[Edited on 24-2-2014 by forgottenpassword]

Zyklon-A - 24-2-2014 at 09:57

Shouldn't this be in Biochemistry?

Random - 24-2-2014 at 11:39

Damn you are doin some really shitty experiments. For a gram of indole you would need to process 10kg of feces. That's sort of A LOT considering how bad they are. Any pics? I mean handling that will be really hard.

Pickardjr - 24-2-2014 at 12:02

Oh man, shaking my head and holding my nose. Why in gods name would you want to do-do
a fecal analysis ? You can buy indole if thats what you are after. Other than that there isn't anything else , other than fertilizer for plants (non-edibale). When I was but a mere bottle washer, I would dream of the array of chemical sources. However now with some bench time under my belt have learned that, one can buy almost anything now days.

SM2 - 24-2-2014 at 12:19

forgotten password,

Skatole, I seem to remember, has a synthesis reference listing in 10th edition of MSD Index. I think the 10th is the 1st one where P2P disappeared mysteriously. It's back in later editions, and I think was in the previous 9th maroon colored cover one.

Apparently, your shitty smelling Skatole (this one, even in dilutions AFAIK), is mentioned to be made by "fusing egg albumin and KOH". So, many health stores sell egg white powder I believe. There is surprisingly no ref. given to the synth I mentioned...it's compound 8388 in the classic 10th (Green) edition of Merck Index.

But why not go with milk instead of eggs. Go with a pure amino acid, instead brute pyrolizing a whole protein. Best of luck.

[Edited on 24-2-2014 by SM2]

forgottenpassword - 24-2-2014 at 13:09

On a small scale extraction would not be worthwhile, I agree. However on the scale of waste processing then many hundreds of kilograms could be processed and indole and skatole extracted and purified. For my TLC analysis I only need about a microgam, so the experiment that I am doing at the moment is only to see how cleanly indole and skatole may be extracted. I suspect that a shorter time than the 24 hours that I am leaving it would probably be better, but for the first extraction I shall see how many compounds are extracted into the DCM, and if the two target compounds are easily separated from the other compounds with a simple chromatographic separation. I wil see how the TLC looks tomorrow. I know the expected Rf values for each so I am hoping that they will be clearly identifiable.

Removal of the malodorous compounds from human waste is an interesting strategy in waste disposal. The fact that some of these chemicals are useful industrial chemicals makes it interesting to explore the idea of large scale extraction. The raw material is free and infinitely abundant, and could easily be more economical than synthesis. Anyway it is just a test at this stage.

[Edited on 24-2-2014 by forgottenpassword]

Random - 24-2-2014 at 13:31

I dunno I read that one vitamin b is produced from sewage somewhere but still I think it's one of the worst things you could recycle. Full of bacteria too. Could also contain dangerous ones depends from whom the feces are. Fermented feces will probably have no skatole left too.

gatewaycityca - 24-2-2014 at 16:18

I've often wondered if there was a way to completely eliminate the 'biological' component of waste so that it could no longer carry bacteria or other harmful pathogens, it might be interesting to see what useful chemicals there could be in it.

I remember reading and seeing on tv a while back about a battery that actually used pee lol. If there was a way to process it so that it was just a chemical and didn't carry bacteria anymore...imagine a waste treatment plant also generating electricity! :D

thesmug - 24-2-2014 at 16:55

Quote: Originally posted by gatewaycityca  
I've often wondered if there was a way to completely eliminate the 'biological' component of waste so that it could no longer carry bacteria or other harmful pathogens, it might be interesting to see what useful chemicals there could be in it.

I remember reading and seeing on tv a while back about a battery that actually used pee lol. If there was a way to process it so that it was just a chemical and didn't carry bacteria anymore...imagine a waste treatment plant also generating electricity! :D

Waste treatment plants use a complex method documented here:
http://www.cleanwaterservices.org/AboutUs/WastewaterAndStorm...
If you want you could attempt to autoclave it (which probably isn't going to work) or dissolve it into solution and disinfect it through any number of disinfection means.
[edit] Here's a direct quote from that page:
Quote:

Our Durham and Rock Creek Advanced Wastewater Treatment Facilities use Sodium Hypochlorite (~12% Bleach) dosed at a controlled level to kill any remaining bacteria. Instrumentation monitors the chlorine residual attained, with an eye toward providing the minimal dosage for complete disinfection. By monitoring a slight excess of dosage, (residual), we ensure that all reactive material in the effluent has been exposed to the disinfecting agent.

Thirty years ago, a chlorine residual of 2 to 3 mg/l was considered good insurance for a proper disinfection of a treatment plant stream. Stream health, however, is not enhanced by the introduction of any chlorine residual into the environment. For this reason, Sodium BiSulfite is now dosed in sufficient quantities to remove residual chlorine before discharge.

At our two smaller plants, Hillsboro and Forest Grove, disinfection is accomplished by means of ultraviolet rays. The cleaned wastewater flow is routed through banks of UV lights, whose intensity is controlled to minimize electrical consumption while maximizing bacterial kill. This system has no need for neutralizing the disinfecting agent before discharge.


[Edited on 2/25/14 by thesmug]